Is Your Is Your Well Water Safe?Well Water Safe?

byby

Bob SchultheisBob SchultheisAgricultural Engineering SpecialistAgricultural Engineering Specialist

MissouriMissouriWater Supply StatisticsWater Supply Statistics

890,000 Missourians on private water supplies

86% on drilled wells 300,000-350,000 active wells 10,000-20,000 new wells drilled annually One abandoned well or cistern for every

80 acres of land (DNR estimate)

– Webster Co. = 4,700+ wells over 379,000 ac.

What is Coliform?What is Coliform?

Coliform bacteria are used as indicator organisms to test for contamination of drinking water.– >1 coliform = “Unsatisfactory” in DOH tests

E. coli is a member of the coliform family and is commonly found in raw sewage.

E. coli is responsible for manyhealth-threatening diseases.

Coliform-Associated Coliform-Associated DiseasesDiseases

Cholera Typhoid Salmonella Shigella Staphylococcus Hepatitis A, B, C Polio Viral Gastroenteritis

1994 Coliform Detection 1994 Coliform Detection StudyStudy

May to Nov. 1994 well survey 9 states- Illinois, Iowa, Kansas,

Minnesota, Missouri, Nebraska,North Dakota, South Dakota, Wisconsin

41.3% tested positive E. coli detects averaged 11.1% Missouri E. coli detects - highest at

22.6%

Sampling Sampling ResultsResults

Private WellsPrivate Wells

Area 1 Area 2 Area 3 Area 4 Area 5 Area 6 Sp Area

0

20

40

60

80

100

TC EC NO3-N

1

2

3 4

5

6

Factors Contributing to Factors Contributing to Coliform DetectsColiform Detects

Improperly constructed wells Poorly maintained wells Ineffective on-site sewage systems Proximity to livestock feeding

operations Karst geologic formations

NitratesNitrates

Nitrate detects are relatively low although not uncommon. (up to 16% of samples)– >10 ppm NO3-N = “Unsatisfactory”

Sources– Livestock facilities (esp. abandoned ones)– N & P fertilizer in excess of crop removal

capability– Failing septic systems

D.O.H. Water Quality D.O.H. Water Quality SurveySurvey

August 1999August 1999

Webster County“gridded” for random sampling

61 participants

D.O.H. Water Quality D.O.H. Water Quality SurveySurvey

August 1999 Results - Webster August 1999 Results - Webster CountyCounty

44%

Private wellstesting positive

for coliform bacteria

28%

Sewage systemswith open discharge& surfacing effluent

Soils in Webster CountySoils in Webster County 79% rated “severe” for pollution 79% rated “severe” for pollution

potentialpotential 21% rated “moderate”21% rated “moderate” 0% rated “slight”0% rated “slight”

“Losing” stream

Solution Channel

What’s Wrong with this What’s Wrong with this Well?Well?

Ways to ReduceWays to Reduce Well Contamination Well Contamination 11

Soil blanket (5+ feet thick) is good filter

Elevation = keep above pollution sources

Distance = 200+ feet horiz. separation

Grout well with neat-cement or bentonite clay by state-certified well driller

Use approved sanitary well cap

Rehab. poorly constructed wells

Ways to ReduceWays to ReduceWell Contamination Well Contamination 22

Plug abandoned wells & cisterns

Repair/move/replace failing septic systems

Apply fertilizer & animal manure according to soil test & manure test

Repair/upgrade animal waste facilities

Install containment for fuels & pesticides

Ways to ReduceWays to ReduceWell Contamination Well Contamination 33

Don’t dump anything into sinkholes

Use grass buffer strips (50+ feet wide)as filters around sinkholes

Promote community awareness of risk

Shock-chlorinate active wells after anyplumbing repairs

Shock-Chlorinating YourShock-Chlorinating Your6-inch Diameter Well 6-inch Diameter Well 11

Remove well cap or unscrew vent pipe

Newer wells Older wells

Shock-Chlorinating YourShock-Chlorinating Your6-inch Diameter Well 6-inch Diameter Well 22

Mix chlorine & water inbucket. Pour into well– Liquid bleach @ 1 pint

per 25’ of water depth, or– Chlorine tablets @ 0.5 lb.

per 150’ of water depth Circulate water back down well Load chlorinated water into

plumbing system

Shock-Chlorinating YourShock-Chlorinating Your6-inch Diameter Well 6-inch Diameter Well 33

Let chlorine water stand insystem at least 12 hours

Flush system with water,starting outside

Retest for bacteria after 7-10 days– $10 cost; DOH has sterile sample bottle – Keep sample cool & dark, get to lab in 6 hours

Keep test results with important papers

University InformationUniversity InformationGuides AvailableGuides Available

WQ100 Water Testing: What to Test For WQ101 Understanding Your Water Test

Report WQ102 Bacteria in Drinking Water WQ103 Nitrate in Drinking Water WQ104 Understanding Home Water

Treatment Systems

Questions??Questions????

Robert A. (Bob) Schultheis

Agricultural Engineering Specialist

Webster County Extension Center

800 S. Marshall, P.O. Box 7

Marshfield, MO 65706-0007

Voice: 417-859-2044

Fax: 417-468-2086

E-mail: schultheisr@missouri.edu

Website: http://outreach.missouri.edu/webster